Since weeds that grow in farms tend to become a nest swarming with vermin of all types, there is a need for cutting those weeds several times a year. Since weed cutting is laborious, various machines have been proposed and put into practical use. Among these machines, bush cutting machines have become popular because they are small in size and easy to manipulate. An example of such bush cutting machines is disclosed in, for example, Japanese Patent Laid-Open Publication No. SHO-61-231039, entitled “VIBRATION ABSORBING GRIP”, and Japanese Utility Model Laid-Open Publication No. SHO-51-144446, entitled “VIBRATION-PROOFING STRUCTURE FOR HANDLE OF BUSH CUTTING MACHINE”.
In the bush cutting machine of SHO-61-231039, a drive shaft housed in a pipe-shaped operation rod is rotated by an engine provided at a proximal end of the operation rod to rotate a disc-shaped cutter provided at a distal end of the operation rod to thereby cut weeds. In use, the bush cutting machine is suspended from a shoulder of an operator who swings the operation rod in fore and aft directions and in right and left directions while gripping left and right grips of a U-shaped handle located midway of the operation rod, to cut the weeds. The left and right grips are made of resilient members for absorbing vibrations.
The bush cutting machine of SHO-51-144446 includes grips provided at right and left portions of a U-shaped handle mounted to an operation handle. The grips are arranged such that elongate core rods, composed of bolts, protrude from right and left distal ends of the handle, and tubular grips are slidably mounted to the respective core rods to allow vibration-proof members such as springs or sponges to be interposed between the core rods and the grips. The vibration-proof members are provided for absorbing vibrations to be imparted to the handle in a longitudinal direction thereof.
In recent years, there is an increasing demand for farm labor environment to be further improved. Even as for bush cutting machines, a demand has grown for more efficiently eliminating vibrations to be transmitted from the handle to the grip so as to reduce farm workers' labor.
However, the bush cutting machine of SHO-61-231039 has a limit in the reduction of vibrations because it relies solely on the elasticity of the right and left elastic grips which absorb vibrations to only an extent.
In the bush cutting machine of SHO-51-14446, the vibration-proof members are provided to absorb vibrations imparted longitudinally of the handle. This arrangement is assumed to work in reducing vibrations applied in such a direction to some extent but not vibrations applied in other directions. Further, the grips are complicated in structure.